Thiocyanato or isothiocyanato substituted naphthalene diimide and rylene diimide compounds and their use as n-type semiconductors

ABSTRACT

Disclosed are thiocyanato or isothiocyanato substituted naphthalene diimide and rylene diimide compounds according to formula (I), use of these compounds as n-type semiconductors, methods of preparing these compounds, as well as various compositions, composites, and devices that incorporate these compounds.

BACKGROUND

Recent developments in organic-based light-emitting diodes (OLEDs),photovoltaics (OPVs), and field-effect transistors (OFETs) have openedup many opportunities in the field of organic electronics. One of thechallenges in this field is to develop thin film devices that haveenvironmentally stable electron-transporting (n-type) organicsemiconductors with high mobility. The performance and stability oforganic n-type materials have significantly lagged behind their p-typecounterparts. Some challenges for advancing the technology of organicn-type materials include their vulnerability to ambient conditions(e.g., air) and solution-processability. For example, it is desirablefor these materials to be soluble in common solvents so that they can beformulated into inks for inexpensive printing processes.

The most common air-stable n-type organic semiconductors includeperfluorinated copper phthalocyanine (CuF₁₆Pc), fluoroacyloligothiophenes (e.g., DFCO-4TCO), N,N′-fluorocarbon-substitutednaphthalene diimides (e.g., NDI-F, NDI-XF), cyano-substituted perylenediimides (e.g., PDI-FCN₂), and cyano-substituted naphthalene diimides(e.g., NDI-8CN₂). See, e.g., Bao et al. (1998), J. Am. Chem. Soc., 120:207-208; de Oteyza et al. (2005), Appl. Phys. Lett., 87: 183504; Schonet al. (2000), Adv Mater. 12: 1539-1542; Ye et al. (2005), Appl. Phys.Lett., 86: 253505; Yoon et al. (2006), J. Am. Chem. Soc., 128:12851-12869; Tong et al. (2006), J. Phys. Chem. B., 110: 17406-17413;Yuan et al. (2004), Thin Solid Films, 450: 316-319; Yoon et al. (2005),J. Am. Chem. Soc., 127: 1348-1349; Katz et al. (2000), J. Am. Chem.Soc., 122: 7787-7792; Katz et al. (2000), Nature (London), 404: 478-481;Katz et al (2001), Chem. Phys. Chem., 3: 167-172; Jung et al. (2006),Appl. Phys. Lett., 88: 183102; Yoo et al. (2006), IEEE Electron DeviceLett., 27: 737-739; Jones et al. (2004), Angew. Chem., Int. Ed. Engl.,43: 6363-6366; and Jones et al. (2007), J. Am. Chem. Soc., 129:15259-15278. Rylene imides are particularly attractive because of theirrobust nature, flexible molecular orbital energetics, and excellentcharge transport properties. However, high-mobility rylene compounds,including PDI-FCN₂ and NDI-F, have poor solubility. Soluble rylenecompounds, on the other hand, usually have poor charge transportproperties.

Accordingly, given potential applications in inexpensive and large-areaorganic electronics that can be produced by high-throughput reel-to-reelmanufacture, the art desires new organic n-type semiconductingcompounds, especially those possessing desirable properties such as airstability, high charge transport efficiency, and good solubility incommon solvents.

SUMMARY

In light of the foregoing, it is an object of the present invention toprovide compounds that can be utilized as organic semiconductors andrelated materials, compositions, composites, and/or devices that canaddress various deficiencies and shortcomings of the state-of-the-art,including those outlined above.

More specifically, the present invention provides thiocyanatosubstituted naphthalene diimide and rylene diimede compounds andderivatives which have semiconducting activity. Materials prepared fromthese compounds have demonstrated unexpected properties and results. Forexample, it has been discovered that, when compared to relatedrepresentative compounds, compounds of the present invention can havehigher carrier mobility and/or better current modulation characteristicsin field-effect devices (e.g., thin-film transistors). In addition, ithas been discovered that compounds of the present invention can possesscertain processing advantages compared to related representativecompounds such as better solubility to permit solution-processabilityand/or good stability at ambient conditions, for example, air stability.Further, the compounds can be embedded with other components forutilization in a variety of semiconductor-based devices.

The problem is solved by compounds of formula I:

wherein:

-   -   R¹ and R², at each occurrence, independently are selected from        H, a C₁₋₃₀ alkyl group, a C₂₋₃₀ alkenyl group, a C₂₋₃₀ alkynyl        group, a C₁₋₃₀ haloalkyl group, and a 3-22 membered cyclic        moiety, each optionally substituted with 1-4 groups        independently selected from halogen, —CN, —NO₂, —C(O)H, —C(O)OH,        —CONH₂, —OH, —NH₂, —CO(C₁₋₁₀ alkyl), —C(O)OC₁₋₁₄ alkyl,        —CONH(C₁₋₁₄ alkyl), —CON(C₁₋₁₄ alkyl)₂, —S—C₁₋₁₄ alkyl,        —O—(CH₂CH₂O)_(n)(C₁₋₁₄ alkyl), —NH(C₁₋₁₄ alkyl), —N(C₁₋₁₄        alkyl)₂, a C₁₋₁₄ alkyl group, a C₂₋₁₄ alkenyl group, a C₂₋₁₄        alkynyl group, a C₁₋₁₄ haloalkyl group, a C₁₋₁₄ alkoxy group, a        C₆₋₁₄ aryl group, a C₃₋₁₄ cycloalkyl group, a 3-14 membered        cycloheteroalkyl group, and a 5-14 membered heteroaryl group; R³        independently are selected from halogen-, CN, —NO₂,        —C(O)O(C₁₋₁₄alkyl), —C(O)O(C₆₋₁₄ aryl), —CHO, C₁₋₁₄ alkylsulfon,        C₆₋₁₄ arylsulfon, a sulfonic acid C₁₋₁₄ alkylester or C₆₋₁₄        arylester group, —CONH₂, —CONH(C₁₋₁₄alkyl), —CONH(C₆₋₁₄ aryl),        —CON(C₁₋₁₄alky)₂, —CON(C₁₋₁₄ alkyl)(C₆₋₁₄ aryl), —CON(C₆₋₁₄        aryl)₂, —C(O)H, a C₁₋₁₄ alkoxy group, a C₁₋₁₄ alkylthio group, a        C₆₋₁₄aryloxy group, a C₆₋₁₄arylthio group, a C₁₋₁₄ alkyl group,        a 3-14 membered cycloheteroalkyl group, a C₆₋₂₀ aryl group and a        5-20 membered heteroaryl group; and    -   n is 0, 1, 2, or 3;    -   x is 0, 1, 2, 3 or 4 if n is >0;    -   y is 1, 2, 3 or 4 if z is 0, and 0, 1, 2, 3 or 4 if z is >0;    -   z is 1, 2, 3 or 4 if y is 0, and 0, 1, 2, 3 or 4 if y is >0.

The present invention also provide methods of preparing such compoundsand semiconductor materials, as well as various compositions,composites, and devices that incorporate the compounds and semiconductormaterials disclosed herein.

The foregoing as well as other features and advantages of the presentinvention will be more fully understood from the following figures,description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates different configurations of field effect transistors.

DETAILED DESCRIPTION

Throughout the description, where compositions are described as having,including, or comprising specific components, or where processes aredescribed as having, including, or comprising specific process steps, itis contemplated that compositions of the present invention also consistessentially of, or consist of, the recited components, and that theprocesses of the present invention also consist essentially of, orconsist of, the recited process steps.

In the application, where an element or component is said to be includedin and/or selected from a list of recited elements or components, itshould be understood that the element or component can be any one of therecited elements or components and can be selected from a groupconsisting of two or more of the recited elements or components.Further, it should be understood that elements and/or features of acomposition, an apparatus, or a method described herein can be combinedin a variety of ways without departing from the spirit and scope of thepresent invention, whether explicit or implicit herein.

The use of the terms “include,” “includes,” “including,” “have,” “has,”or “having” should be generally understood as open-ended andnon-limiting unless specifically stated otherwise.

The use of the singular herein includes the plural (and vice versa)unless specifically stated otherwise.

As used herein, “halo” or “halogen” refers to fluoro, chloro, bromo, andiodo.

As used herein, “alkoxy” refers to —O-alkyl group. Examples of alkoxygroups include, but are not limited to, methoxy, ethoxy, propoxy (e.g.,n-propoxy and isopropoxy), t-butoxy groups, and the like. The alkylgroup in the —O-alkyl group can be substituted as described herein.

As used herein, “alkylthio” refers to an —S-alkyl group. Examples ofalkylthio groups include, but are not limited to, methylthio, ethylthio,propylthio (e.g., n-propylthio and isopropylthio), t-butylthio groups,and the like. The alkyl group in the —S-alkyl group can be substitutedas described herein.

As used herein, “oxo” refers to a double-bonded oxygen (i.e., ═O).

R¹, R² can be a C₁₋₃₀alkyl group. As used herein, “alkyl” refers to astraight-chain or branched saturated hydrocarbon group. Examples ofalkyl groups include methyl (Me), ethyl (Et), propyl (e.g., n-propyl andisopropyl), butyl (e.g., n-butyl, isobutyl, s-butyl, t-butyl), pentylgroups (e.g., n-pentyl, isopentyl, neopentyl), and the like. An alkylgroup can have 1 to 30 carbon atoms, for example 1 to 20 carbon atoms(i.e., C₁₋₂₀ alkyl group). A lower alkyl group typically has up to 4carbon atoms. Examples of lower alkyl groups include methyl, ethyl,propyl (e.g., n-propyl and isopropyl), and butyl groups (e.g., n-butyl,isobutyl, s-butyl, t-butyl). In some embodiments, alkyl groups can besubstituted as disclosed herein.

R¹, R² can be a C₁₋₃₀haloalkyl group. As used herein, “haloalkyl” refersto an alkyl group having one or more halogen substituents. A haloalkylgroup can have 1 to 30 carbon atoms, for example 1 to 10 carbon atoms(i.e., C₁₋₁₀ haloalkyl group). Examples of haloalkyl groups include CF₃,C₂F₅, CHF₂, CH₂F, CCl₃, CHCl₂, CH₂Cl, C₂Cl₅, and the like. Perhaloalkylgroups, i.e., alkyl groups wherein all of the hydrogen atoms arereplaced with halogen atoms (e.g., CF₃ and C₂F₅), are included withinthe definition of “haloalkyl.” For example, a C₁₋₂₀ haloalkyl group canhave the formula —C_(a)H_(2a+1−b)X_(b), wherein X, at each occurrence,is F, Cl, Br, or I, a is an integer in the range of 1 to 20, and b is aninteger in the range of 1 to 41, provided that b is not greater than2a+1.

R¹, R² can be a C₂₋₃₀alkenyl group. As used herein, “alkenyl” refers toa straight-chain or branched alkyl group having one or morecarbon-carbon double bonds. In various embodiments, an alkenyl group canhave 2 to 30 carbon atoms, for example, 2 to 10 carbon atoms (i.e.,C₂₋₁₀ alkenyl group). Examples of alkenyl groups include, but are notlimited to, ethenyl, propenyl, butenyl, pentenyl, hexenyl, butadienyl,pentadienyl, hexadienyl groups, and the like. The one or morecarbon-carbon double bonds can be internal (such as in 2-butene) orterminal (such as in 1-butene). In some embodiments, alkenyl groups canbe substituted as disclosed herein.

R¹, R² can be a C₂₋₃₀alkynyl group. As used herein, “alkynyl” refers toa straight-chain or branched alkyl group having one or more triplecarbon-carbon bonds. Examples of alkynyl groups include ethynyl,propynyl, butynyl, pentynyl, and the like. The one or more triplecarbon-carbon bonds can be internal (such as in 2-butyne) or terminal(such as in 1-butyne). In various embodiments, an alkynyl group can have2 to 30 carbon atoms, for example, 2 to 10 carbon atoms (i.e., C₂₋₁₀alkynyl group). In some embodiments, alkynyl groups can be substitutedas disclosed herein.

R¹, R² can be a 3-22 membered cyclic moiety. As used herein, a “cyclicmoiety” can include one or more (e.g., 1-6) carbocyclic or heterocyclicrings. The cyclic moiety can be a cycloalkyl group, a heterocycloalkylgroup, an aryl group, or a heteroaryl group (i.e., can include onlysaturated bonds, or can include one or more unsaturated bonds regardlessof aromaticity), each including, for example, 3-22 ring atoms, and canbe optionally substituted as described herein. In some embodiments wherethe cyclic moiety is a monocyclic moiety, the monocyclic moiety caninclude a 3-14 membered aromatic or non-aromatic, carbocyclic orheterocyclic ring. A monocyclic moiety can include, for example, aphenyl group or a 5- or 6-membered heteroaryl group, each of which canbe optionally substituted as described herein. In some embodiments wherethe cyclic moiety is a polycyclic moiety, the polycyclic moiety caninclude two or more rings fused to each other or connected to each othervia a single bond or a spiro atom, or one or more bridged atoms. Apolycyclic moiety can include an 8-22 membered aromatic or non-aromatic,carbocyclic or heterocyclic ring, such as a C₈₋₂₂ aryl group or an 8-22membered heteroaryl group, each of which can be optionally substitutedas described herein.

R¹, R² can be a cycloalkyl group having 3 to 22 carbon atoms. As usedherein, “cycloalkyl” refers to a non-aromatic carbocyclic groupincluding cyclized alkyl, alkenyl, and alkynyl groups. The cycloalkylgroup can have 3 to 22 carbon atoms, for example, 3 to 14 carbon atoms(i.e., C₃₋₁₄ cycloalkyl group). The cycloalkyl group can be monocyclic(e.g., cyclohexyl) or polycyclic (e.g., containing fused, bridged,and/or spiro ring systems), wherein the carbon atoms are located insideor outside of the ring system. Examples of cycloalkyl groups include,but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptyl, cyclopentenyl, cyclohexenyl, cyclohexadienyl,cycloheptatrienyl, norbornyl, norpinyl, norcaryl, adamantyl, andspiro[4.5]decanyl groups, as well as their homologs, isomers, and thelike. In some embodiments, cycloalkyl groups can be substituted asdisclosed herein.

As used herein, “heteroatom” refers to an atom of any element other thancarbon or hydrogen and includes, for example, nitrogen, oxygen, silicon,sulfur, phosphorus, and selenium.

R¹, R² can be a cycloheteroalkyl group having 3 to 22 ring atoms. Asused herein, “cycloheteroalkyl” refers to a non-aromatic cycloalkylgroup that contains at least one ring heteroatom selected from O, S, Se,N, P, and Si (e.g., O, S, and N), and optionally contains one or moredouble or triple bonds. A cycloheteroalkyl group can have 3 to 22 ringatoms, for example, 3 to 14 ring atoms (i.e., 3-14 memberedcycloheteroalkyl group). One or more N, P, S, or Se atoms (e.g., N or S)in a cycloheteroalkyl ring may be oxidized (e.g., morpholine N-oxide,thiomorpholine S-oxide, thiomorpholine S,S-dioxide). In someembodiments, nitrogen or phosphorus atoms of cycloheteroalkyl groups canbear a substituent, for example, a hydrogen atom, an alkyl group, orother substituents as described herein. Cycloheteroalkyl groups can alsocontain one or more oxo groups, such as oxopiperidyl, oxooxazolidyl,dioxo-(1H,3H)-pyrimidyl, oxo-2(1H)-pyridyl, and the like. Examples ofcycloheteroalkyl groups include, among others, morpholinyl,thiomorpholinyl, pyranyl, imidazolidinyl, imidazolinyl, oxazolidinyl,pyrazolidinyl, pyrazolinyl, pyrrolidinyl, pyrrolinyl, tetrahydrofuranyl,tetrahydrothiophenyl, piperidinyl, piperazinyl, and the like. In someembodiments, cycloheteroalkyl groups can be substituted as disclosedherein.

R¹, R² can be an aryl group having from 6 to 22 ring atoms. As usedherein, “aryl” refers to an aromatic monocyclic hydrocarbon ring systemor a polycyclic ring system in which two or more aromatic hydrocarbonrings are fused (i.e., having a bond in common with) together or atleast one aromatic monocyclic hydrocarbon ring is fused to one or morecycloalkyl and/or cycloheteroalkyl rings. An aryl group can have from 6to 22 ring atoms in its ring system, for example, 6 to 14 ring atoms(i.e., C₆₋₁₄ aryl group), which can include multiple fused rings. Insome embodiments, a polycyclic aryl group can have from 8 to 22 carbonatoms. Any suitable ring position of the aryl group can be covalentlylinked to the defined chemical structure. Examples of aryl groups havingonly aromatic carbocyclic ring(s) include, but are not limited to,phenyl, 1-naphthyl (bicyclic), 2-naphthyl (bicyclic), anthracenyl(tricyclic), phenanthrenyl (tricyclic) and like groups. Examples ofpolycyclic ring systems in which at least one aromatic carbocyclic ringis fused to one or more cycloalkyl and/or cycloheteroalkyl ringsinclude, among others, benzo derivatives of cyclopentane (i.e., anindanyl group, which is a 5,6-bicyclic cycloalkyl/aromatic ring system),cyclohexane (i.e., a tetrahydronaphthyl group, which is a 6,6-bicycliccycloalkyl/aromatic ring system), imidazoline (i.e., a benzimidazolinylgroup, which is a 5,6-bicyclic cycloheteroalkyl/aromatic ring system),and pyran (i.e., a chromenyl group, which is a 6,6-bicycliccycloheteroalkyl/aromatic ring system). Other examples of aryl groupsinclude, but are not limited to, benzodioxanyl, benzodioxolyl,chromanyl, indolinyl groups, and the like. In some embodiments, arylgroups can be substituted as disclosed herein. In some embodiments, anaryl group can have one or more halogen substituents and can be referredto as a “haloaryl” group. Perhaloaryl groups, i.e., aryl groups whereall of the hydrogen atoms are replaced with halogen atoms (e.g., —C₆F₅),are included within the definition of “haloaryl.” In certainembodiments, an aryl group is substituted with another aryl group andcan be referred to as a biaryl group. Each of the aryl groups in thebiaryl group can be substituted as disclosed herein.

R¹, R² can be a heteroaryl group having 5 to 22 ring atoms. As usedherein, “heteroaryl” refers to an aromatic monocyclic ring systemcontaining at least one ring heteroatom selected from O, N, S, Si, andSe or a polycyclic ring system where at least one of the rings presentin the ring system is aromatic and contains at least one ringheteroatom. Polycyclic heteroaryl groups include two or more heteroarylrings fused together and monocyclic heteroaryl rings fused to one ormore aromatic carbocyclic rings, non-aromatic carbocyclic rings, and/ornon-aromatic cycloheteroalkyl rings. A heteroaryl group, as a whole, canhave from 5 to 22 ring atoms (e.g., 5-14 membered heteroaryl group) andcontain 1-5 ring heteroatoms. The heteroaryl group can be attached tothe defined chemical structure at any heteroatom or carbon atom thatresults in a stable structure. Generally, heteroaryl rings do notcontain O—O, S—S, or S—O bonds. However, one or more N or S atoms in aheteroaryl group can be oxidized (e.g., pyridine N-oxide, thiopheneS-oxide, thiophene S,S-dioxide). Examples of heteroaryl groups include,for example, the 5- or 6-membered monocyclic and 5-6 bicyclic ringsystems shown below:

where T is O, S, NH, N-alkyl, N-aryl, N-(arylalkyl) (e.g., N-benzyl),SiH₂, SiH-(alkyl), Si(alkyl)₂, SiH-(arylalkyl), Si-(arylalkyl)₂, orSi(alkyl)(arylalkyl). Examples of heteroaryl groups include pyrrolyl,furyl, thienyl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, triazolyl,tetrazolyl, pyrazolyl, imidazolyl, isothiazolyl, thiazolyl,thiadiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, indolyl, isoindolyl,benzofuryl, benzothienyl, quinolyl, 2-methylquinolyl, isoquinolyl,quinoxalyl, quinazolyl, benzotriazolyl, benzimidazolyl, benzothiazolyl,benzisothiazolyl, benzisoxazolyl, benzoxadiazolyl, benzoxazolyl,cinnolinyl, 1H-indazolyl, 2H-indazolyl, indolizinyl, isobenzofuyl,naphthyridinyl, phthalazinyl, pteridinyl, purinyl, oxazolopyridinyl,thiazolopyridinyl, imidazopyridinyl, furopyridinyl, thienopyridinyl,pyridopyrimidinyl, pyridopyrazinyl, pyridopyridazinyl, thienothiazolyl,thienoxazolyl, thienoimidazolyl, and the like. Further examples ofheteroaryl groups include, but are not limited to,4,5,6,7-tetrahydroindolyl, tetrahydroquinolyl, benzothienopyridyl,benzofuropyridyl, and the like. In some embodiments, heteroaryl groupscan be substituted as disclosed herein.

Compounds of the present invention can include a “divalent group”defined herein as a linking group capable of forming a covalent bondwith two other moieties. For example, compounds of the present inventioncan include a divalent C₁₋₂₀ alkyl group, such as, for example, amethylene group.

At various places in the present specification, substituents ofcompounds are disclosed in groups or in ranges. It is specificallyintended that the description include each and every individualsubcombination of the members of such groups and ranges. For example,the term “C₁₋₆ alkyl” is specifically intended to individually discloseC₁, C₂, C₃, C₄, C₅, C₆, C₁-C₆, C₁-C₅, C₁-C₄, C₁-C₃, C₁-C₂, C₂-C₆, C₂-C₅,C₂-C₄, C₂-C₃, C₃-C₆, C₃-C₅, C₃-C₄, C₄-C₆, C₄-C₅, and C₅-C₆ alkyl. By wayof other examples, an integer in the range of 0 to 40 is specificallyintended to individually disclose 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40, and an integer in therange of 1 to 20 is specifically intended to individually disclose 1, 2,3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.Additional examples include that the phrase “optionally substituted with1-5 substituents” is specifically intended to individually disclose achemical group that can include 0, 1, 2, 3, 4, 5, 0-5, 0-4, 0-3, 0-2,0-1, 1-5, 1-4, 1-3, 1-2, 2-5, 2-4, 2-3, 3-5, 3-4, and 4-5 substituents.

Compounds described herein can contain an asymmetric atom (also referredas a chiral center) and some of the compounds can contain two or moreasymmetric atoms or centers, which can thus give rise to optical isomers(enantiomers) and diastereomers (geometric isomers). The presentinvention include such optical isomers and diastereomers, includingtheir respective resolved enantiomerically or diastereomerically pureisomers (e.g., (+) or (−) stereoisomer) and their racemic mixtures, aswell as other mixtures of the enantiomers and diastereomers. In someembodiments, optical isomers can be obtained in enantiomericallyenriched or pure form by standard procedures known to those skilled inthe art, which include, for example, chiral separation, diastereomericsalt or ester formation, kinetic resolution, enzymatic resolution, andasymmetric synthesis. The present invention also encompass cis and transisomers of compounds containing alkenyl moieties (e.g., alkenes andimines). It is also understood that the present invention encompass allpossible regioisomers in pure form and mixtures thereof, which can beobtained with standard separation procedures known to those skilled inthe art, for examples, column chromatography, thin-layer chromatography,simulated moving-bed chromatography, and high-performance liquidchromatography. For example, perylene compounds of the present inventioninclude perylene derivatives in their pure form or mixtures thereof,where the perylene derivatives can be substituted with 1, 2, 3, 4, 5, 6,7, or 8 substituents. Naphthalene compounds of the present inventioninclude naphthalene derivatives in their pure form or mixtures thereof,where the naphthalene derivatives can be substituted with 1, 2, 3 or 4substituents. Specifically, the perylene derivatives can includecompounds having the moiety:

where Y, at each occurrence, can be H, a thiocyanato or anisothiocyanato group.

In various embodiments, two of the Y groups are H and the other two Ygroups independently are a thiocyanato or an isothiocyanato group.Accordingly, in the embodiments where two of the Y groups are H and theother two independently area thiocyanato or an isothiocyanato group,compounds of the present invention can have regioisomers having theformulae:

In certain embodiments, compounds of the present invention can includecompounds having formula i or ii:

or mixtures thereof, where Y independently is a thiocyanato group or anisothiocyanato group.

As used herein, a “p-type semiconducting material” or a “p-typesemiconductor” refers to a semiconducting material having holes as themajority current carriers. In some embodiments, when a p-typesemiconducting material is deposited on a substrate, it can provide ahole mobility in excess of about 10⁻⁵ cm²/Vs. In the case offield-effect devices, a p-type semiconductor can also exhibit a currenton/off ratio of greater than about 10.

As used herein, a “n-type semiconducting material” or a “n-typesemiconductor” refers to a semiconducting material having electrons asthe majority current carriers. In some embodiments, when a n-typesemiconducting material is deposited on a substrate, it can provide anelectron mobility in excess of about 10⁻⁵ cm²/Vs. In the case offield-effect devices, an n-type semiconductor can also exhibit a currenton/off ratio of greater than about 10.

As used herein, “field effect mobility” refers to a measure of thevelocity with which charge carriers, for example, holes (or units ofpositive charge) in the case of a p-type semiconducting material andelectrons in the case of an n-type semiconducting material, move throughthe material under the influence of an electric field.

As used herein, a compound can be considered “ambient stable” or “stableat ambient conditions” when the carrier mobility or thereduction-potential of the compound is maintained at about its initialmeasurement when the compound is exposed to ambient conditions, forexample, air, ambient temperature, and humidity over a period of time.For example, a compound can be described as ambient stable if itscarrier mobility or reduction potential does not vary more than 20% ormore than 10% from its initial value after exposure to ambientconditions, i.e., air, humidity and temperature, over a 3 day, 5 day, or10 day period.

As used herein, “solution-processable” refers to compounds, materials,or compositions that can be used in various solution-phase processesincluding spin-coating, printing (e.g., inkjet printing, screenprinting, pad printing, gravure printing, flexographic printing, offsetprinting, microcontact printing, and lithographic printing), spraying,electrospray coating, drop casting, zone-casting, dip coating, and bladecoating.

At various places in the present application temperatures are disclosedin ranges. It is specifically intended that the description includesnarrower ranges of temperatures within such ranges, as well as themaximum and minimum temperatures embracing such range of temperatures.

Throughout the specification, structures may or may not be presentedwith chemical names. Where any question arises as to nomenclature, thestructure prevails.

In one aspect, the present invention provide compounds having formulaIa, Ib or Ic:

wherein: R¹ and R² are as defined above.

In a further aspect, the present invention provides compounds havingformula Id, Ie, or If:

wherein R¹, R² are as defined above.R¹ and R², at each occurrence, are independently selected from H, aC₁₋₃₀ alkyl group, a C₂₋₃₀ alkenyl group, a C₂₋₃₀ alkynyl group, a C₁₋₃₀haloalkyl group, and a 3-22 membered cyclic moiety, each optionallysubstituted with 1-4 groups independently selected from halogen, —CN,—NO₂, —C(O)H, —C(O)OH, —CONH₂, —OH, —NH₂, —CO(C₁₋₁₄ alkyl), —C(O)CO₁₋₁₄alkyl, —CONH(C₁₋₁₄ alkyl), —CON(C₁₋₁₄ alkyl)₂, —S—C₁₋₁₄ alkyl,—O—(CH₂CH₂O)_(n)(C₁₋₁₄ alkyl), —NH(C₁₋₁₄ alkyl), —N(C₁₋₁₄ alkyl)₂, aC₁₋₁₄ alkyl group, a C₂₋₁₄ alkenyl group, a C₂₋₁₄ alkynyl group, a C₁₋₁₄haloalkyl group, a C₁₋₁₄ alkoxy group, a C₆₋₁₄ aryl group, a C₃₋₁₄cycloalkyl group, a 3-14 membered cycloheteroalkyl group, and a 5-14membered heteroaryl group, and n is as described herein. The 3-22membered cyclic moiety can be selected from a C₆₋₂₂ aryl group, a 5-22membered heteroaryl group, a C₃₋₂₂ cycloalkyl group, and a 3-22 memberedcycloheteroalkyl group, each of which can be optionally substituted asdescribed herein.

In preferred embodiments, R¹ and R², at each occurrence, areindependently selected from a C₁₋₁₂ alkyl group, a C₁₋₁₂ haloalkylgroup, and a 5-14 membered monocyclic moiety, each optionallysubstituted with 1-4 groups independently selected from halogen, —CN,—NO₂, —C(O)H, —C(O)OH, —CONH₂, —OH, —NH₂, —CO(C₁₋₁₄ alkyl), —C(O)OC₁₋₁₄alkyl, —CONH(C₁₋₁₄ alkyl), —CON(C₁₋₁₄ alkyl)₂, —S—C₁₋₁₄ alkyl,—O—(CH₂CH₂O)_(n)(C₁₋₁₄ alkyl), —NH(C₁₋₁₄ alkyl), —N(C₁₋₁₄ alkyl)₂, aC₁₋₁₄ alkyl group, a C₂₋₁₄ alkenyl group, a C₂₋₁₄ alkynyl group, a C₁₋₁₄haloalkyl group, a C₁₋₁₄ alkoxy group, a C₆₋₁₄ aryl group, a C₃₋₁₄cycloalkyl group, a 3-14 membered cycloheteroalkyl group, and a 5-14membered heteroaryl group, and n is 1, 2, or 3.

In particular embodiments, R¹ and R², at each occurrence, areindependently selected from a C₁₋₁₂ alkyl group, a C₁₋₁₂ haloalkylgroup, a C₇₋₂₀ arylalkyl group, and a phenyl group, wherein the phenylgroup is optionally substituted with 1-4 groups independently selectedfrom a halogen, a C₁₋₆ alkyl group, and a C₁₋₆ haloalkyl group. Forexample, R¹ and R², at each occurrence, are selected from —CH₃, —C₂H₅,—C₃H₇, —C₄H₉, —C₅H₁₁, —C₆H₁₃, —C₈H₁₇ (in particular 2-ethylhexyl),—C₁₂H₂₅, —C₁₃H₂₇, a phenyl group optionally substituted with 1-5 halogroups or C₁₋₆ alkyl groups, a C₇₋₁₂ phenylalkyl group wherein phenyl isoptionally substituted with 1-5 halo groups in particular F atoms, orC₁₋₆ alkyl groups, and a C₁₋₆ haloalkyl group.

Examples of particular haloalkyl groups are —CF₃, —C₂F₅, —C₃F₇ and—CH₂C₃F₇.

Examples of particular arylalkyl groups are benzyl, phenylethyl andphenylpropyl.

In various embodiments, R³ is an electronic-withdrawing groupindependently selected from halogen, —CN, —NO₂, —CF₃, —OCF₃, —CO₂(C₁₋₁₀alkyl), —CHO, C₁-C₁₄ alkylsulfon, C₆₋₁₄ arylsulfon, a sulfonic acid—C₁₋₁₄ alkylester or —C₆₋₁₄ arylester group, —CONH(C₁₋₁₀ alkyl),—CON(C₁₋₁₀ alkyl)₂. For example R³ can be halogen, —CN, —NO₂, —CF₃, or—OCF₃.

In certain embodiments, R³ is F, Cl, Br, I, or —CN.

In another aspect, the present invention provides methods of preparingcompounds as disclosed herein. In various embodiments, the method caninclude reacting a compound of formula IIa and Ilb, respectively

with a thiocyanate,wherein R¹ and R² are as defined above, X, at each occurrence, is H or aleaving group, suitable leaving groups are F, Cl, Br, I, —OSO₂—C₆H₄—CH₃,—OSO₂—CH₃.

In various embodiments, X, at each occurrence, can be H or halogen. Forexample, X, at each occurrence, can be H, F, Cl, Br, or I. In certainembodiments, X, at each occurrence, can be H or Br.

In some embodiments, the thiocyanate is LiSCN, NaSCN, KSCN, NH₄SCN,NR₄SCN, PR₄SCN, wherein R are each independently C₁₋₁₈ alkyl, CuSCN orAgSCN. Preferably, the thiocyanate is NaSCN or KSCN.

In some embodiments, the reaction can be conducted at room temperature,for example, between 20° C. and 30° C. In some embodiments, the reactioncan be conducted at a temperature that is different from roomtemperature. For example, the temperature can be lower or higher thanroom temperature. In certain embodiments, the reaction can be conductedat an elevated temperature, i.e., a temperature higher than roomtemperature. For example, the elevated temperature can be between 50° C.and 300° C. In particular embodiments, the elevated temperature can bebetween 50° C. and 180° C., for example, between 70° C. and 150° C.(e.g., 70° C. or 150° C.).

Whether the thiocyanato-compound or the isothiocyanato-compound isformed may depend on the nature of the solvent.

Solvents in which the thiocyanato-compound is predominantly or almostexclusively formed include DMSO, mixtures of DMSO with aromatic solventssuch as toluene, xylene, mesitylene, tetraline, chlorobenzene,dichlorobenzene, chloronapthalene or nitrobenzene, or mixtures of DMSOwith an ether such as 1,4-dioxan or tetrahydrofuran.

Solvents in which the isothiocyanato-compound is predominantly or almostexclusively formed include methyl ethyl ketone and isobutyl methylketone. Reaction in the presence of a phase transfer catalyst such as aquaternary ammonia salt favors the formation of the isothiocyanatocompound.

In any case, where mixtures of thiocyanato-, isothiocyanato- and mixedthiocyanatoisothiocyanato-compounds are formed, the pure compounds canbe isolated by standard methods, such as chromatography.

In various embodiments, a compound of formula IIa and IIb, respectively,can be prepared by reacting a compound of formula IIIa and IIIb,respectively

with an primary amine R¹—NH₂ or R²—NH₂ in an aprotic solvent, wherein X,R¹ and R² are as defined herein. This is preferred for the preparationof compounds IIb.

However, in case of the preparation of compounds IIa, it is morepreferred to chlorineate or brominate a naphthalene diimide compound offormula Va.

using a chlorination and a bromination agent respectively.

This may result in higher yields of compounds IIa, as compared to thebromination of naphthalenetetracarboxylic acid dianhydride IVa and thesubsequent imidation of compounds IIIa with R¹—NH₂ and/or R²—NH₂.

The present invention also concerns a process for producing abromo-substituted naphthalene diimide compound of formula IIa

wherein X are independently H, Cl or Br with the proviso that at leastone X is Cl or Br, R¹, R² are as defined in claim 1,comprising the step of chlorinating or brominating naphthalene diimideof formula Va

using a chlorination and a bromination agent, respectively.

Preferred chlorination and bromination agents areN,N′-dichloroisocyanuric acid and N,N′-dibromoisocyanuric acid,respectively.

The chlorination is preferably carried out in concentrated sulfuric acidas reaction medium (e.g. 95-98 wt.-% sulfuric acid). FeCl₃ and FeBr₃,respectively, can be added as catalysts.

The naphthalene diimide compound of formula IIa is preferably obtainedby reacting naphthalenetetracarboxylic acid dianhydride with a primaryamine R¹—NH₂, R²—NH₂, or mixtures thereof, wherein R¹, R² are as definedherein.

In various embodiments, the aprotic solvent can include an ether. Insome embodiments, the aprotic solvent can include (C₁₋₆alkyl)O(CH₂CH₂O)_(m)(C₁₋₆ alkyl), where m can be 1, 2, 3, 4, 5, or 6. Inparticular embodiments, the aprotic solvent can be a solvent or asolvent mixture that includes triethylene glycol dimethyl ether. Forexample, the aprotic solvent can be triethylene glycol dimethyl ether.

In various embodiments, the reaction can be conducted at roomtemperature. In various embodiments, the reaction can be conducted at atemperature that is different from room temperature. For example, thetemperature can be lower or higher than room temperature. In certainembodiments, the reaction can be conducted at an elevated temperature,i.e., a temperature higher than room temperature. For example, theelevated temperature can be between 50° C. and 300° C. In particularembodiments, the elevated temperature can be between 50° C. and 200° C.,for example, between 70° C. and 180° C. (e.g., 165° C.).

Compounds of formula IIIa and IIIb, respectively, can be prepared bybromination of compounds of formula IVa and IVb, respectively,

using known bromination agents such as bromine, N,N′-dibromoisocyanuricacid or Nbromosuccinimide.

Bromination of compound IVb is described in DE 195 47 209 and in F.Würthner, Chem. Commun. 2004, 1564-1579. The bromination of perylenediimdes is described in J. Org. Chem. 2007, 72, 5973-5979.

Compounds of the present invention can be prepared in accordance withthe procedures outlined in Scheme 1 below, from commercially availablestarting materials, compounds known in the literature, or readilyprepared intermediates, by employing standard synthetic methods andprocedures known to those skilled in the art. Standard synthetic methodsand procedures for the preparation of organic molecules and functionalgroup transformations and manipulations can be readily obtained from therelevant scientific literature or from standard textbooks in the field.It will be appreciated that where typical or preferred processconditions (i.e., reaction temperatures, times, mole ratios ofreactants, solvents, pressures, etc.) are given, other processconditions can also be used unless otherwise stated. Optimum reactionconditions can vary with the particular reactants or solvent used, butsuch conditions can be determined by one skilled in the art by routineoptimization procedures. Those skilled in the art of organic synthesiswill recognize that the nature and order of the synthetic steps can bevaried for the purpose of optimizing the formation of the compoundsdescribed herein.

The processes described herein can be monitored according to anysuitable method known in the art. For example, product formation can bemonitored by spectroscopic means, such as nuclear magnetic resonancespectroscopy (NMR, e.g., ¹H or ¹³C), infrared spectroscopy (IR),spectrophotometry (e.g., UV-visible), mass spectrometry (MS), or bychromatography such as high pressure liquid chromatograpy (HPLC), gaschromatography (GC), gel-permeation chromatography (GPC), or thin layerchromatography (TLC).

The reactions or the processes described herein can be carried out insuitable solvents which can be readily selected by one skilled in theart of organic synthesis. Suitable solvents typically are substantiallynonreactive with the reactants, intermediates, and/or products at thetemperatures at which the reactions are carried out, i.e., temperaturesthat can range from the solvent's freezing temperature to the solvent'sboiling temperature. A given reaction can be carried out in one solventor a mixture of more than one solvent. Depending on the particularreaction step, suitable solvents for a particular reaction step can beselected.

As shown in Scheme 1, perylene-3,4:9,10-tetracarboxylic acid dianhydride(PDA), a, can be brominated at 1,7-positions to provide PDA-Br₂, b,which upon reacting with a primary amine can provide abis(dicarboximide), c. The substitution of the bromo groups in c bythiocyanato groups can produce a dithiocyanato-substitutedbis(dicarboximide), d. Although not shown in Scheme 1, the brominationof a can also produce regioisomers of b, for example,1,6-dibromo-perylene-3,4:9,10-tetracarboxylic acid dianhydride,subsequently resulting in regioisomers of d, for example,1,6-dithiocyanato bis(dicarboximide). Instead of PDA, thebis(dicarboximide) resulting from the amination of a can be likewisebrominated to give compound c.

In an analogous way, naphthalenedithiocyanato bis(dicarboximide) can beprepared from naphthalene-3,4:7,8-tetracarboxylic acid dianhydrideaccording to Scheme 2:

However, it is preferred to prepare the naphthalenedithiocyanatobis(dicarboximide) compounds following Scheme 3:

Compounds of formula I can be used to prepare semiconductor materials(e.g., compositions and composites), which in turn can be used tofabricate various articles of manufacture, structures, and devices.Semiconductor materials incorporating one or more compounds of thepresent invention can exhibit n-type semiconducting activity.

As the compounds disclosed herein are soluble in common solvents, thepresent invention can offer processing advantages in fabricatingelectrical devices such as thin film semiconductors, field-effectdevices, organic light emitting diodes (OLEDs), organic photovoltaics,photodetectors, capacitors, and sensors. As used herein, a compound canbe considered soluble in a solvent when at least 1 mg of the compoundcan be dissolved in 1 mL of the solvent. Examples of common organicsolvents include petroleum ethers; acetonitrile; aromatic hydrocarbonssuch as benzene, toluene, xylene, and mesitylene; ketones such asacetone and methyl ethyl ketone; ethers such as tetrahydrofuran,dioxane, bis(2-methoxyethyl)ether, diethyl ether, di-isopropyl ether,and t-butyl methyl ether; alcohols such as methanol, ethanol, butanol,and isopropyl alcohol; aliphatic hydrocarbons such as hexanes; acetatessuch as methyl acetate, ethyl acetate, methyl formate, ethyl formate,isopropyl acetate, and butyl acetate; amides such as dimethylformamideand dimethylacetamide; sulfoxides such as dimethylsulfoxide; halogenatedaliphatic and aromatic hydrocarbons such as dichloromethane, chloroform,ethylene chloride, chlorobenzene, dichlorobenzene, and trichlorobenzene;and cyclic solvents such as cyclopentanone, cyclohexanone, and2-methypyrrolidone. Examples of common inorganic solvents include waterand ionic liquids.

Accordingly, the present invention further provides compositions thatinclude one or more compounds disclosed herein dissolved or dispersed ina liquid medium, for example, an organic solvent, an inorganic solvent,or combinations thereof (e.g., a mixture of organic solvents, inorganicsolvents, or organic and inorganic solvents). In some embodiments, thecomposition can further include one or more additives independentlyselected from detergents, dispersants, binding agents, compatiblizingagents, curing agents, initiators, humectants, antifoaming agents,wetting agents, pH modifiers, biocides, and bactereriostats. Forexample, surfactants and/or other polymers (e.g., polystyrene,polyethylene, poly-alpha-methylstyrene, polyisobutene, polypropylene,polymethylmethacrylate, and the like) can be included as a dispersant, abinding agent, a compatiblizing agent, and/or an antifoaming agent. Insome embodiments, such compositions can include one or more compoundsdisclosed herein, for example, two or more different compounds of thepresent invention can be dissolved in an organic solvent to prepare acomposition for deposition. In certain embodiments, the composition caninclude two or more regioisomers. Further, it should be understood thatthe devices described herein also can comprise one or more compounds ofthe present invention, for example, two or more regioisomers asdescribed herein.

Various deposition techniques, including various solution-processingtechniques, have been used in preparing organic electronics. Forexample, much of the printed electronics technology has focused oninkjet printing, primarily because this technique offers greater controlover feature position and multilayer registration. Inkjet printing is anon-contact process, which offers the benefits of not requiring apreformed master (compared to contact printing techniques), as well asdigital control of ink ejection, thereby providing drop-on-demandprinting. Micro dispensing is another non-contact method of printing.However, contact printing techniques have the key advantage of beingwellsuited for very fast roll-to-roll processing. Exemplary contactprinting techniques include, but are not limited to, screen-printing,gravure printing, offset printing, flexographic printing, lithographicprinting, pad printing, and microcontact printing. As used herein,“printing” includes a noncontact process, for example, injet printing,micro dispensing, and the like, and a contact process, for example,screen-printing, gravure printing, offset printing, flexographicprinting, lithographic printing, pad printing, microcontact printing,and the like. Other solution processing techniques include, for example,spin coating, drop-casting, zone casting, dip coating, blade coating, orspraying. In addition, the deposition step can be carried out by vacuumvapor-deposition.

The present invention, therefore, further provide methods of preparing asemiconductor material. The methods can include preparing a compositionthat includes one or more compounds disclosed herein dissolved ordispersed in a liquid medium such as a solvent or a mixture of solvents,and depositing the composition on a substrate to provide a semiconductormaterial (e.g., a thin film semiconductor) that includes one or morecompounds disclosed herein. In various embodiments, the liquid mediumcan be an organic solvent, an inorganic solvent such as water, orcombinations thereof. In some embodiments, the composition can furtherinclude one or more additives independently selected from viscositymodulators, detergents, dispersants, binding agents, compatiblizingagents, curing agents, initiators, humectants, antifoaming agents,wetting agents, pH modifiers, biocides, and bactereriostats. Forexample, surfactants and/or polymers (e.g., polystyrene, polyethylene,poly-alpha-methylstyrene, polyisobutene, polypropylene,polymethylmethacrylate, and the like) can be included as a dispersant, abinding agent, a compatiblizing agent, and/or an antifoaming agent. Insome embodiments, the depositing step can be carried out by printing,including inkjet printing and various contact printing techniques (e.g.,screen-printing, gravure printing, offset printing, pad printing,lithographic printing, flexographic printing, and microcontactprinting). In other embodiments, the depositing step can be carried outby spin coating, drop-casting, zone casting, dip coating, blade coating,or spraying.

Various articles of manufacture including electronic devices, opticaldevices, and optoelectronic devices such as field effect transistors(e.g., thin film transistors), photovoltaics, organic light emittingdiodes (OLEDs), complementary metal oxide semiconductors (CMOSs),complementary inverters, D flip-flops, rectifiers, and ring oscillators,that make use of the compounds and the semicondutor materials disclosedherein also as well as methods of making the same are within the scopeof the present invention. Accordingly, the present invention providesarticles of manufacture such as the various devices described hereinthat include a composite having a semiconductor material of the presentinvention, a substrate component, and/or a dielectric component. Thesubstrate component can be selected from materials including dopedsilicon, an indium tin oxide (ITO), ITO-coated glass, ITO-coatedpolyimide or other plastics, aluminum or other metals alone or coated ona polymer or other substrate, a doped polythiophene or other polymers,and the like. The dielectric component can be prepared from inorganicdielectric materials such as various oxides (e.g., SiO₂, Al₂O₃, HfO₂),organic dielectric materials such as various polymeric materials (e.g.,polycarbonate, polyester, polystyrene, polyhaloethylene, polyacrylate),self-assembled superlattice/self-assembled nanodielectric (SAS/SAND)materials (e.g., described in Yoon, M-H. et al., PNAS, 102 (13):4678-4682 (2005), the entire disclosure of which is incorporated byreference herein), and hybrid organic/inorganic dielectric materials(e.g., described in U.S. patent application Ser. No. 11/642,504, theentire disclosure of which is incorporated by reference herein). In someembodiments, the dielectric component can include the crosslinkedpolymer blends described in U.S. patent application Ser. Nos.11/315,076, 60/816,952, and 60/861,308, the entire disclosure of each ofwhich is incorporated by reference herein. The composite also caninclude one or more electrical contacts. Suitable materials for thesource, drain, and gate electrodes include metals (e.g., Au, Al, Ni,Cu), transparent conducting oxides (e.g., ITO, IZO, ZITO, GZO, GIO,GITO), and conducting polymers (e.g.,poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS),polyaniline (PANI), polypyrrole (PPy)). One or more of the compositesdescribed herein can be incorporated within various organic electronic,optical, and optoelectronic devices such as organic thin filmtransistors (OTFTs), specifically, organic field effect transistors(OFETs), as well as sensors, capacitors, unipolar circuits,complementary circuits (e.g., inverter circuits), and the like.

An aspect of the present invention, therefore, relates to methods offabricating an organic field effect transistor that incorporates asemiconductor material of the present invention. The semiconductormaterials of the present invention can be used to fabricate varioustypes of organic field effect transistors including top-gate top-contactcapacitor structures, top-gate bottom-contact capacitor structures,bottom-gate top-contact capacitor structures, and bottom-gatebottom-contact capacitor structures. FIG. 1 illustrates the four commontypes of OFET structures: top-contact bottom-gate structure (top left),bottom-contact bottom-gate structure (top right), bottom-contacttop-gate structure (bottom left), and top-contact top-gate structure(bottom right). As shown in FIG. 1, an OFET can include a dielectriclayer (e.g., shown as 8, 8′, 8″, and 8″), a semiconductor layer (e.g.,shown as 6, 6′, 6″, and 6″), a gate contact (e.g., shown as 10, 10′,10″, and 10″), a substrate (e.g., shown as 12, 12′, 12″, and 12″), andsource and drain contacts (e.g., shown as 2, 2′, 2″, 2′″, 4, 4′, 4″, and4′″).

In certain embodiments, OTFT devices can be fabricated with the presentcompounds on doped silicon substrates, using SiO₂ as the dielectric, intop-contact geometries. In particular embodiments, the activesemiconducting layer which incorporates at least a compound of thepresent invention can be deposited by vacuum vapor deposition at roomtemperature or at an elevated temperature. In other embodiments, theactive semiconducting layer which incorporates at least a compound ofthe present invention can be applied by solution-based process, forexample, spin-coating or jet printing. For top-contact devices, metalliccontacts can be patterned on top of the films using shadow masks.

In certain embodiments, OTFT devices can be fabricated with the presentcompounds on plastic foils, using polymers as the dielectric, intop-gate bottom-contact geometries. In particular embodiments, theactive semiconducting layer which incorporates at least a compound ofthe present invention can be deposited at room temperature or at anelevated temperature. In other embodiments, the active semiconductinglayer which incorporates at least a compound of the present inventioncan be applied by spin-coating or printing as described herein. Gate andsource/drain contacts can be made of Au, other metals, or conductingpolymers and deposited by vapor-deposition and/or printing.

Other articles of manufacture in which compounds of the presentinvention are useful are photovoltaics or solar cells. Compounds of thepresent invention can exhibit broad optical absorption and/or a verypositively shifted reduction potential making them desirable for suchapplications. Accordingly, the compounds described herein can be used asan n-type semiconductor in a photovoltaic design, which includes anadjacent p-type semiconducting material that forms a p-n junction. Thecompounds can be in the form of a thin film semiconductor, which can bea composite of the thin film semiconductor deposited on a substrate.Exploitation of compounds of the present invention in such devices iswithin the knowledge of the skilled artisan.

Accordingly, another aspect of the present invention relates to methodsof fabricating an organic light-emitting transistor, an organiclight-emitting diode (OLED), or an organic photovoltaic device thatincorporates one or more semiconductor materials of the presentinvention.

The following examples are provided to illustrate further and tofacilitate understanding of the present invention and are not in any wayintended to limit the invention.

Unless otherwise noted, all reagents were purchased from commercialsources and used without further purification. Some reagents weresynthesized according to known procedures. Anhydrous tetrahydrofuran(THF) was distilled from sodium/benzophenone. Reactions were carried outunder nitrogen unless otherwise noted. UV-Vis spectra were recorded on aCary Model 1 UV-vis spectrophotometer. NMR spectra were recorded on aVarian Unity Plus 500 spectrometer and a 400 MHz spectrometer (¹H, 400MHz and 500 MHz; ¹³C, 125 MHz). Electrospray mass spectrometry wasperformed on a Thermo Finnegan model LCQ Advantage mass spectrometer.

EXAMPLES

FIG. 1 shows the four common types of OFET structures: top-contactbottom-gate structure (top left), bottom-contact bottom-gate structure(top right), bottom-contact top-gate structure (bottom left), andtop-contact top-gate structure (bottom right).

FIG. 2 a shows the drain current in μA versus the drain-source voltagein V at different gate-source voltages for the compound of example 1a.

FIG. 2 b shows the drain current in A versus the gate-source voltage inV at a drain-source voltage of 1.5 V for the compound of example 1b.

FIG. 2 c shows the electron mobility in cm²/Vs versus the gate-sourcevoltage at a drain-source voltage of 1.5 V for the compound of example1b.

FIG. 2 d shows the drain current in A versus the gate-source voltage inV at a drain-source voltage of 50 V for the compound of example 4b.

FIG. 2 e shows the electron mobility in cm²/Vs versus the gate-sourcevoltage at a drain-source voltage of 50 V for the compound of example4b.

FIG. 3 a shows the drain current in A versus the drain-source voltage inV at different gate-source voltages for the compound of example 3.

FIG. 3 b shows the drain-source current in A versus the gate-sourcevoltage in V (upper curve) and the square root of the drain-sourcecurrent in A^(1/2) versus the gate-source voltage in V (lower curve) forthe compound of example 3.

Example 1 Example 1a Preparation of2,6-Dibromo-N,N′-bis(1H,1H-perfluorobutyl)-naphthalene[1,8:4,5]-bis(dicarboximide)

To a solution of 2.00 g (3.17 mmol)N,N′-bis(1H,1H-perfluorobutyl)naphthalene[1,8:4,5]-bis(dicarboximide)[described in H. E. Katz et al., Materials Research Society SymposiumProceedings (2002), 665 (Electronics, Optical and OptoelectronicPolymers and Oligomers), 271-280] in 240 ml of 95 to 97% strengthsulfuric acid was added 1.17 g (3.96 mmol) of 97% strengthN,N′-dibromoisocyanuric acid at room temperature. The reaction flask wasdarkened with aluminium foil. The solution was stirred for 28 hours atroom temperature. Subsequently, the solution was poured on 1.5 kg iceand neutralized with NaOH. The aqueous phase was extracted twice with750 ml dichloromethane. The combined organic extracts were dried overmagnesium sulfate, filtered and concentrated to dryness. The residue wassuspended in n-heptane and filtered. The filter cake obtained was driedto yield 2.29 g of a yellow solid. Recrystallization from 80 mlisobutanol yielded 2.06 g (83% of the theoretical amount) of a yellowsolid showing only one spot in thin-layer chromatography.

¹H-NMR (400 MHz, D₈-THF): δ=9.00 (s, 2H), 5.08 (t, 4H) ppm.

Example 1b Preparation ofN,N′-Bis(1H,1H-perfluorobutyl)-2,6-dithiocyanato-naphthalene[1,8:4,5]-bis(dicarboximide)

To a solution of 0.50 g (0.63 mmol)N,N′-bis(1H,1H-perfluorobutyl)-2,6-dibromonaphthalene[1,8:4,5]bis(dicarboximide)in 50 ml dimethyl sulfoxide was added within 2 hours 0.128 g (1.59 mmol)sodium thiocyanate at 95° C. while stirring continuously. The solutionwas stirred for another hour at 95° C. and cooled to room temperature.Then 150 ml of water were added to the reaction solution, whereby aprecipitate was formed. The precipitate was filtered, washed with waterand dried. The crude product was suspended in 200 ml ofmethylcyclohexane, heated under reflux for one hour and filtered whilehot. The filter cake was washed with light petroleum and dried. Thisyielded 0.207 g of a yellowish brown solid which was purified bychromatography on silica gel.

¹H-NMR (400 MHz, CD₂Cl₂): δ=9.32 (s, 2H), 5.05 (t, 4H) ppm.

Example 2 Preparation ofN,N′-Bis(1H,1H-perfluorobutyl)-2-isothiocyanato-6-thiocyanatonaphthalene[1,8:4,5]-bis(dicarboximide)

To a solution of 0.50 g (0.64 mmol)2,6-dibromo-N,N′-bis(1H,1H-perfluorobutyl)-naphthalene[1,8:4,5]bis(dicarboximide)and 0.0056 g (0.013 mmol) Aliquat® 134 (a phase transfer catalyst) in 50ml isobutyl methyl ketone was added within 3 hours a solution of 0.13 g(1.6 mmol) sodium thiocyanate in isobutyl methyl ketone at 95° C. Thesolution was stirred for another 2 hours at 95° C. and cooled to roomtemperature. After the addition of 3 g of silica gel the solution wasconcentrated to dryness. The crude product was purified bychromatography on silica gel using dichloromethane as eluent. Thisyielded 0.075 g (15% of the theoretical amount) of a ochre-coloredsolid.

¹H-NMR (400 MHz, CD₂Cl₂): δ=9.28 (s, 1H), 8.70 (s, 1H), 5.06 (t, 2H),5.00 (t, 2H) ppm.

Example 3 Preparation ofN,N′-Bis(phenethyl)-1,7(6)-dithiocyanatoperylene[3,4:9,10]-bis(dicarboximide)

A solution of 0.50 g (0.65 mmol)2,6-dibromo-N,N′-bis(phenethyl)-perylene-[3,4:9,10]bis(dicarboximide)(described in US 2007/0259475) in 12 ml dimethyl sulfoxide and 12 mlchlorobenzene was heated to 95° C. Then a solution of 0.13 g (1.6 mmol)sodium thiocyanate in 15 ml dimethyl sulfoxide was slowly added withinone hour. The reaction solution was maintained at this temperature for 5hours. After the reaction solution was cooled to room temperaturechlorobenzene was removed by evaporation. 50 ml of water were added,whereby a precipitate was formed. The precipitate was filtered, washedwith water and methanol and subsequently dried. The dark-red coloredcrude product was purified twice by chromatography on silica gel usingtoluene/ethyl acetate (20:1) as eluent. This yielded 0.11 g (24% of thetheoretical amount) of a dark-red colored solid.

¹H-NMR (400 MHz, CD₂Cl₂): δ=9.09 (s, 2H), 8.80 (d, 2H), 8.47 (d, 2H),7.10-7.42 (m, 10H), 4.45 (t, 4H), 3.08 (t, 4H) ppm.

Example 4 Example 4a Preparation ofN,N′-Bis(1-methylpentyl)-1,7(6)-dibromo-perylene[3,4:9,10]-bis(dicarboximide)

A suspension of 8.03 g (14.6 mmol)1,7(6)-dibromo-perylene[3,4:9,10]tetracarbonic acid dianhydride (mixtureof 1,7- and 1,6-Dibromo isomers) [described in DE 19547209] and 3.12 g(30.8 mmol) (S)-(+)-2-aminohexane in 120 ml anhydrous 1,4-dioxane washeated to 160° C. in a Roth reactor and maintained at that temperaturefor 1 hour while stirring continuously. After the reaction solution wascooled to room temperature 450 ml methanol were added. The mixture wasstirred for 5 hours. The precipitate was filtered, washed with methanoland subsequently dried. The dark-red colored crude product was purifiedby chromatography on silica gel using dichloromethane as eluent. Thisyielded 5.24 g (50% of the theoretical amount) of a dark-red coloredsolid

¹H-NMR (400 MHz, CDCl₃): δ=9.48 (d, 2H), 8.90 (s, 2H), 8.69 (d, 2H),5.28 (m, 2H), 2.24 (m, 2H), 1.92 (m, 2H), 1.60 (m, 6H), 1.35 (m, 6H),1.25 (m, 2H), 0.87 (t, 6H) ppm.

Example 4b Preparation ofN,N′-Bis(1-methylpentyl)-1,7(6)-dithiocyanato-perylene[3,4:9,10]-bis(dicarboximide)

To a solution of 0.50 g (0.70 mmol)N,N′-bis(1-methylpentyl)-1,7(6)-dibromo-perylene[3,4:9,10]bis(dicarboximide)in 25 ml dimethyl sulfoxide was added within 1.5 hours a solution of0.12 g (1.5 mmol) sodium thiocyanate in 10 ml dimethyl sulfoxide at 95°C. while stirring continuously. The solution was stirred for another 21hours at 95° C. and cooled to room temperature. Then 150 ml water wereadded to the solution, whereby a precipitate was formed. The precipitatewas filtered, washed with water and methanol and subsequently dried. Thedark-red colored crude product was purified by chromatography on silicagel using dichloromethane as eluent. This yielded 0.30 g (64% of thetheoretical amount) dark-red colored solid. The proportion of the1,6-dithiocyanato isomer was 11% according to ¹H NMR spectroscopy.

¹H NMR (500 MHz, CDCl₃) of the 1,7-dithiocyanato isomer: δ=9.10 (s, 2H),8.80 (d, 2H), 8.47 (d, 2H), 5.29 (m, 2H), 2.23 (m, 2H), 1.94 (m, 2H),1.61 (m, 6H), 1.35 (m, 6H), 1.25 (m, 2H), 0.88 (t, 6H) ppm.

¹H NMR (500 MHz, CDCl₃) of the 1,6-dithiocyanato isomer: δ=9.12 (s, 2H),8.81 (d, 2H), 8.40 (d, 2H) ppm; only the signals in the aromatic regioncould be assigned.

The pure 1,7-dithiocyanato isomer with a melting point of 229-230° C.(decomposition from 225° C.) could be obtained by recrystallization fromisopropanol.

Example 5 Preparation of a mixture of 2,6(7)-dichloro- and2,6,7-trichloro-N,N″-bis(1H,1H-perfluorbutyl)-naphthalene[1,8:4,5]-bis(dicarboximide)

To a solution of 0.50 g (0.79 mmol)N,N′-bis(1H,1H-perfluorobutyl)naphthalene[1,8:4,5]-bis(dicarboximide),described in H. E. Katz et al., Materials Research Society SymposiumProceedings (2002), 665 (Electronics, Optical and OptoelectronicPolymers and Oligomers), 271-280, in 60 ml of 95-97 wt.-% sulfuric acidwere added 1.06 g (5.4 mmol) of N,N″-dichloro-isocyanuric acid. Afterstirring for 30 min at room temperature, the solution was heated to 85°C. and maintained for 24 h at this temperature. The reaction solutionwas cooled to room temperature and diluted with 11 of ice water, wherebya yellow solid precipitated. The suspension was stirred for 1 h and thenneutralized with diluted NaOH. The solid was separated by a glas fritand washed with warm water. To the dry solid, methylene chloride wasadded. The yellow solution was filtered and evaporated to dryness. Theresidue was dried and purified by chromatography using silica gel andmethylene chloride/cyclohexane (65:35) as mobile phase. Two mainfractions were obtained and each evaporated and concentrated to giveyellow solids. One fraction of 0.18 g (33% of the theoretical amount)contained 50% by weight of the trichloro-compound and 50% by weight ofthe two isomeric dichloro-compounds, according to ¹H-NMR data. The otherfraction of 0.070 g (13% of the theoretical amount) contained 66% byweight of the trichloro-compound and 34% by weight of the two isomericdichloro-compounds, according to ¹H-NMR data.

Example 6 Fabrication of Vapor-Deposited OFETs a) General Procedure forthe Fabrication of Vapor-Deposited OFETs in the Top-ContactConfiguration

Highly doped p-type silicon (100) wafers (0.01-0.02 Ω·cm) were used assubstrates A. Highly doped p-type silicon (100) wafers (0.005-0.02 Ω·cm)with a 100 nm thick thermally grown SiO₂ layer (capacitance 34 nF/cm²)were used as substrates B.

Onto substrates A, a 30 nm thick layer of aluminum is deposited bythermal evaporation in a Leybold UNIVEX 300 vacuum evaporator from atungsten wire, at a pressure of 2×10⁻⁶ mbar and with an evaporation rateof 1 nm/s. The surface of the aluminum layer is oxidized by a briefexposure to an oxygen plasma in an Oxford reactive ion etcher (RIE,oxygen flow rate: 30 sccm, pressure: 10 mTorr, plasma power: 200 W,plasma duration 30 sec) and the substrate is then immersed into a2-propanol solution of a phosphonic acid (1 mMol solution ofC₁₄H₂₉PO(OH)₂ [TDPA] or 1 mMol solution of C₇F₁₅C₁₁H₂₂PO(OH)₂ [FODPA])and left in the solution for 1 hour, which results in the formation of aself-assembled monolayer (SAM) of phosphonic acid molecules on thealuminum oxide surface. The substrate is taken out of the solution andrinsed with pure 2-propanol, dried in a stream of nitrogen and left for10 min on a hotplate at a temperature of 100° C. The total capacitanceof the AlO_(x)/SAM gate dielectric on substrate A is 810 nF/cm² in caseof C₁₄H₂₉PO(OH)₂ and 710 nF/cm² in case of C₇F₁₅C₁₁H₂₂PO(OH)₂. Onsubstrates B, an about 8 nm thick layer of Al₂O₃ is deposited by atomiclayer deposition in a Cambridge NanoTech Savannah (80 cycles at asubstrate temperature of 250° C.). The surface of the aluminum oxidelayer is activated by a brief exposure to an oxygen plasma in an Oxfordreactive ion etcher (RIE, oxygen flow rate: 30 sccm, pressure: 10 mTorr,plasma power: 200 W, plasma duration 30 sec) and the substrate is thenimmersed into a 2-propanol solution of a phosphonic acid (1 mMolsolution of C₁₄H₂₉PO(OH)₂ [TDPA] or 1 mMol solution ofC₇F₁₅C₁₁H₂₂PO(OH)₂ [FODPA]) and left in the solution for 1 hour, whichresults in the formation of a self-assembled monolayer (SAM) ofphosphonic acid molecules on the aluminum oxide surface. The substrateis taken out of the solution and rinsed with pure 2-propanol, dried in astream of nitrogen and left for 10 min on a hotplate at a temperature of100° C. The total capacitance of the SiO₂/AlO_(x)/SAM gate dielectric onsubstrate B is 32 nF/cm² (independent on the choice of the phosphonicacid).

The contact angle of water on the TDPA-treated substrates is 108°, andon the FODPA-treated substrates 118°.

A 30 nm thick film of the organic semiconductor is deposited by thermalsublimation in a Leybold UNIVEX 300 vacuum evaporator from a molybdenumboat, at a pressure of 2×10⁻⁶ mbar and with an evaporation rate of 0.3nm/s.

For the source and drain contacts 30 nm of gold is evaporated through ashadow mask in a Leybold UNIVEX 300 vacuum evaporator from tungstenboat, at a pressure of 2×10⁻⁶ mbar and with an evaporation rate of 0.3nm/s. The transistors have a channel length (L) ranging from 10 to 100μm and a channel width (W) ranging from 50 to 1000 μm.

To be able to contact the back side of the silicon wafer, the wafer(which also serves as the gate electrode of the transistors) isscratched on the back side and coated with silver ink.

The electrical characteristics of the transistors are measured on aMicromanipulator 6200 probe station using an Agilent 4156C semiconductorparameter analyzer. All measurements are performed in air at roomtemperature. The probe needles are brought into contact with the sourceand drain contacts of the transistors by putting them down carefully ontop of the gold contacts. The gate electrode is contacted through themetal substrate holder onto which the wafer is placed during themeasurements.

To obtain the transfer curve the drain-source voltage (V_(DS)) is heldto 3 V (in case of substrate A) or 40 V (in case of substrate B). Thegate-source voltage V_(GS) is swept at medium speed from 0 to 3 V insteps of 0.03 V (substrate A) or from 0 to 40 V in steps of 0.4 V(substrate B) and back. The charge-carrier mobility is extracted in thesaturation regime from the slope of (I_(D))^(1/2) versus V_(GS).

To obtain the output characteristics the drain-source voltage (V_(DS))is swept at medium speed from 0 to 3 V in steps of 0.03 V (substrate A)and from 0 to 40 V in steps of 0.4 V (substrate B), while thegate-source voltage V_(GS) is held at up to 8 different voltages (e.g.0, 0.5, 1, 1.5, 2, 2.5, 3 V in case of substrate A or 0, 10, 20, 30, 40V in case of substrate B). Exemplary plots are given in FIGS. 2 a-2 cfor the compound of example 1b and in FIGS. 2 d and 2 e for the compoundof example 4b.

b) Table 1 gives the field-effect mobilities (μ) and on/off ratios(I_(on)/I_(off)) for compounds of example 1b and 4b with a thin(substrate A) and a thick (substrate B) gate dielectric withC₁₄H₂₉PO(OH)₂ (TDPA) for the SAM at a certain substrate temperature(T_(sub)) measured in ambient air.

TABLE 1 Compound Substrate from temperature Electron mobility On/offratio example Substrate T_(sub) [° C.] μ [cm²/Vs] I_(on)/I_(off) 1b A110 0.051 10⁵ 4b B 70 1.9 · 10⁻⁶ n.d.

Example 7

Procedure for a solution-processed OFET with the compound of example 3on a standard substrate in the bottom-gate bottom-contact configuration

A 0.5% solution of the compound of example 3 in chloroform warmed to 50°C. was spincoated (Spin Coater: Primus STT15) on an untreated standardsilicium substrate at 5000 rpm. The standard silicium substrateconsisted of a silicium wafer with a 230 nm thick siliciumdioxid layer(∈_(r)=3.9) and D/S contacts with gold (30 nm) and ITO as an adhesive.

The electrical characteristics of the transistor was measured with anAgilent 4155C Semiconductor Parameter Analyzer. The transistor had achannel length (W) of 10 mm and a channel width (L) of 10 μm. Allmeasurements were performed in air at room temperature.

To obtain the transfer curve the drain-source voltage (U_(DS)) is heldto 40 V. The gate-source voltage U_(GS) is swept at medium speed from−20 to 40 V in steps of 2 V and back. The charge-carrier mobility isextracted in the saturation regime from the slope of (I_(D))^(1/2)versus V_(GS). The respective plot is shown in FIG. 3 b.

To obtain the output characteristics the drain-source voltage (V_(DS))is swept at medium speed from 0 to 40 V in steps of 2 V, while thegate-source voltage V_(is) is held at up to 4 different voltages (10,20, 30, 40 V). The respective plot is shown in FIG. 3 a.

An electron mobility of μ=1.7×10⁻⁶ cm²/Vs and an on/off ratio of 2.4×10³were obtained.

1. A compound of formula I:

wherein: R¹ and R², at each occurrence, independently are selected fromH, a C₁₋₃₀ alkyl group, a C₂₋₃₀ alkenyl group, a C₂₋₃₀ alkynyl group, aC₁₋₃₀ haloalkyl group, and a 3-22 membered cyclic moiety, eachoptionally substituted with 1-4 groups independently selected fromhalogen, —CN, —NO₂, —C(O)H, —C(O)OH, —CONH₂, —OH, —NH₂, —CO(C₁₋₁₄alkyl), —C(O)OC₁₋₁₄ alkyl, —CONH(C₁₋₁₄ alkyl), —CON(C₁₋₁₄ alkyl)₂,—S—C₁₋₁₄ alkyl, —O—(CH₂CH₂O)_(n)(C₁₋₁₄ alkyl), —NH(C₁₋₁₄ alkyl),—N(C₁₋₁₄ alkyl)₂, a C₁₋₁₄ alkyl group, a C₂₋₁₄ alkenyl group, a C₂₋₁₄alkynyl group, a C₁₋₁₄ haloalkyl group, a C₁₋₁₄ alkoxy group, a C₆₋₁₄aryl group, a C₃₋₁₄ cycloalkyl group, a 3-14 membered cycloheteroalkylgroup, and a 5-14 membered heteroaryl group; R³ independently areselected from halogen, —CN, —NO₂, —C(O)O(C₁₋₁₄ alkyl), —C(O)O(C₆₋₁₄aryl), —CHO, C₁₋₁₄ alkylsulfon, C₆₋₁₄ arylsulfon, a sulfonic acid C₁₋₁₄alkylester or C₆₋₁₄ arylester group, —CONH₂, —CONH(C₁₋₁₄ alkyl),—CONH(C₆₋₁₄′ aryl), —CON(C₁₋₁₄ alkyl)₂, —CON(C₁₋₁₄ alkyl)(C₆₋₁₄ aryl),—CON(C₆₋₁₄ aryl)₂, —C(O)H, a C₁₋₁₄ alkoxy group, a C₁₋₁₄ alkylthiogroup, a C₆₋₁₄ aryloxy group, a C₆₋₁₄ arylthio group, a C₁₋₁₄ alkylgroup, a 3-14 membered cycloheteroalkyl group, a C₆₋₂₀ aryl group and a5-20 membered heteroaryl group; and n is 0, 1, 2, or 3; x is 0, 1, 2, 3or 4; y is 1, 2, 3 or 4 if z is 0, and 0, 1, 2, 3 or 4 if z is >0; z is1, 2, 3 or 4 if y is 0, and 0, 1, 2, 3 or 4 if y is >0.
 2. The compoundof claim 1, wherein R¹ and R², at each occurrence, are selected from aC₁₋₁₂ alkyl group, a C₁₋₁₂ haloalkyl group, and a C₇₋₂₀ arylalkyl group.3. The compound of claim 1 or claim 2, wherein R¹ and R² is selectedform a C₁₋₁₂ alkyl group, a C₁₋₁₂ fluoroalkyl group and a C₇₋₁₂phenylalkyl group, wherein phenyl is optionally substituted with 1-5halogen atoms.
 4. The compound of any one of claims 1-3, wherein n=0. 5.The compound of any one of claims 1-3, wherein n=1.
 6. The compound ofany one of claims 1-5, wherein x=0, y=0 and z=2.
 7. The compound of anyone of claims 1-6, wherein x=0, y=1 and z=1.
 8. The compound of any oneof claims 1-6, wherein x=0, y=2 and z=0.
 9. The compound of any one ofclaims 1-8, the compound having formula Ia, Ib or Ic:

wherein R¹ and R² are as defined in any of claims 1-3.
 10. The compoundof any one of claims 1-8, the compound having the formula:

wherein R¹ and R² are as defined in any of claims 1-3.
 11. A thin filmsemiconductor comprising one or more compounds of any one of claims1-10.
 12. A field effect transistor device comprising the thin filmsemiconductor of claim
 11. 13. A photovoltaic device comprising the thinfilm semiconductor of claim
 11. 14. An organic light emitting diodedevice comprising the thin film semiconductor of claim
 11. 15. Aunipolar or complementary circuit device comprising the thin filmsemiconducfor of claim
 11. 16. A process for producing a chloro- orbromo-substituted naphthalene diimide compound of formula IIa

wherein X are independently H, Cl or Br with the proviso that at leastone X is Cl or Br, R¹, R² are as defined in claim 1, comprising the stepof chlorinating or brominating naphthalene diimide of formula Va

using a chlorination agent and a bromination agent, respectively. 17.The process of claim 16, wherein the chlorination agent is N,N′dichloroisocyanuric acid and the bromination agent isN,N′-dibromoisocyanuric acid.
 18. The process of claim 16 or 17, whereinthe naphthalene diimide compound of formula Va is obtained by reactingnaphthalene tetracarboxylic acid dianhydride of formula IVa

with a primary amine R¹—NH₂ and/or R²—NH₂.